package class01;

import java.util.Arrays;

public class Code06_InsertionSort {

  public static void insertionSort(int[] arr) {
    if (arr == null || arr.length < 2) {
      return;
    }
    for (int i = 1; i < arr.length; i++) { // 0 ~ i 做到有序
      for (int j = i - 1; j >= 0 && arr[j] > arr[j + 1]; j--) {
        swap(arr, j, j + 1);
      }
    }
  }

  // i和j,数交换
  public static void swap(int[] arr, int i, int j) {
    int tmp = arr[i];
    arr[i] = arr[j];
    arr[j] = tmp;
  }

  // for test
  public static void comparator(int[] arr) {
    Arrays.sort(arr);
  }

  // for test
  public static int[] generateRandomArray(int maxSize, int maxValue) {
    // Math.random() ->  [0,1) 所有的小数，等概率返回一个
    // Math.random() * N -> [0,N) 所有小数，等概率返回一个
    // (int)(Math.random() * N) -> [0,N-1] 所有的整数，等概率返回一个
    int[] arr = new int[(int) ((maxSize + 1) * Math.random())]; // 长度随机
    for (int i = 0; i < arr.length; i++) {
      arr[i] = (int) ((maxValue + 1) * Math.random()) - (int) (maxValue * Math.random());
    }
    return arr;
  }

  // for test
  public static int[] copyArray(int[] arr) {
    if (arr == null) {
      return null;
    }
    int[] res = new int[arr.length];
    for (int i = 0; i < arr.length; i++) {
      res[i] = arr[i];
    }
    return res;
  }

  // for test
  public static boolean isEqual(int[] arr1, int[] arr2) {
    if ((arr1 == null && arr2 != null) || (arr1 != null && arr2 == null)) {
      return false;
    }
    if (arr1 == null && arr2 == null) {
      return true;
    }
    if (arr1.length != arr2.length) {
      return false;
    }
    for (int i = 0; i < arr1.length; i++) {
      if (arr1[i] != arr2[i]) {
        return false;
      }
    }
    return true;
  }

  // for test
  public static void printArray(int[] arr) {
    if (arr == null) {
      return;
    }
    for (int i = 0; i < arr.length; i++) {
      System.out.print(arr[i] + " ");
    }
    System.out.println();
  }

  // for test
  public static void main(String[] args) {
    int testTime = 500000;
    int maxSize = 100; // 随机数组的长度0～100
    int maxValue = 100; // 值：-100～100
    boolean succeed = true;
    for (int i = 0; i < testTime; i++) {
      int[] arr1 = generateRandomArray(maxSize, maxValue);
      int[] arr2 = copyArray(arr1);
      insertionSort(arr1);
      comparator(arr2);
      if (!isEqual(arr1, arr2)) {
        // 打印arr1
        // 打印arr2
        succeed = false;
        break;
      }
    }
    System.out.println(succeed ? "Nice!" : "Fucking fucked!");

    int[] arr = generateRandomArray(maxSize, maxValue);
    printArray(arr);
    insertionSort(arr);
    printArray(arr);
  }
}
